This is some seriously fantastic news. Not to mention that the fact that it's Mark Gurman reporting on this, which gives it an almost 100% chance of happening. I had been very interested in the iPad Pro and Apple Pencil for both sketching and design work, as well as future potential 3d sculpting uses, and photo retouching. Unfortunately my love for the device was quickly squelched by the overwhelming size of the device. It was just simply too big for me to deal with. A normal sized iPad with the iPad Pro's specs would be exactly up my alley, especially since it will likely knock $100 off of the entry fee.
Apple still has quite a few issues to deal with on the iOS side of things in getting professionals interested in the platform, but this commitment to building pro level devices on iOS leads me to believe they have some stuff up their sleeves for iOS 10 and 11 to fix a lot of that.
Heck, If you see Apple marketing iOS 10 as iOS X then you REALLY know they are willing to bring some more serious software to their mobile platform.